This useful invention (Shaw's Spiral Exhaust Nozzle) has been reported on by a Committee of the Institute, who in concluding their very favourable Report, recommend the grant of a premium and a medal to the inventor, and remark: 'In view of the annoyance, fright, and danger arising from the roar of escaping steam, and of the completeness with which the nozzle destroys this roar, we are of the opinion that Mr Shaw has done a great service to the community, and particularly to the transportation interests, in overcoming an obnoxious and dangerous feature in the use of steam.' The nozzle, we are informed, has already been largely adopted in America. Shall we have long to wait for its introduction here? People who dwell in the neighbourhood of factories and thousands of travellers, are ready to give it a welcome.
Steam-power for tramways instead of horse-power continues to be a subject of experiment, with a view to prevent noise and escape of steam, so that passengers may not be deafened nor horses frightened. It was stated at a meeting of the Institution of Civil Engineers, that the best form of tramway is that which has the rails laid on continuous wooden sleepers, and that there will not be so great a saving as is commonly supposed by using steam instead of horses, for the repairs of the engines will be a heavy item of expense, and the engine-fitters and drivers will require high wages. Some inventors dispense with steam and make use of compressed air; and mention was made of 'a pneumatic car designed by Mr Scott Moncrieff which had been at work on the Yale of Clyde tramways. It carries one hundred cubic feet of air at a pressure of three hundred and fifty pounds on the square inch; and considering that everything about it was of a rough and temporary character, the success obtained was encouraging.' As regards capability, we are told that 'on the level, and on gradients up to one in thirty, engines can do all that is necessary. But the engine has yet to be designed which will stop and start again, with a heavy car behind it, on any steeper inclination without trouble and delay.'
On the other side of the Atlantic, a different conclusion has been arrived at, for, as stated in the _Journal of the Franklin Institute_, a steam tramway engine has been tried in Baltimore which, with a load of a hundred passengers, can be easily stopped and started on a gradient of seven feet in the hundred, or nearly three hundred and seventy feet per mile. It drew the same load through snow and slush ten inches deep, when four horses were required to draw an ordinary car. This engine weighs sixteen thousand pounds. On suburban roads it travels at from twelve to eighteen miles an hour. Compared with a two-horse car, it shews, in its working expenses, a saving of five hundred and fifty-eight dollars in a year. The power of traction is, however, of less importance than the absence of smoke and of noise from the steam that is employed. Several good specimens of smokeless and noiseless tramway engines have been shewn in this country.